Parametric Excitation of Ion-Acoustic Waves in a Fully Ionized, Bounded Plasma

摘要

Parametric excitation of ion-acoustic waves in the fully ionized bounded plasma in a Q-machine is demonstrated by periodic variation of the electron temperature. The electron temperature is controlled by nonresonant radio-frequency heating, the periodic variation of the electron temperature being achieved by amplitude modulation of the rf power. A model based on the ion-acoustic wave equation for the bounded geometry and the Mathieu equation with appropriate nonlinear terms is found to be in agreement with experimental results such as growth rates, amplitude saturation, phase effects, threshold values, and symmetry properties of the resonance curves. (Author)